Project 2: Improving the Accuracy of Diagnosis of Cancer in Children with HIV Infection The goal of Project 2 is to evaluate and implement novel strategies that are reproducible and sustainable across treatment sites in sub-Saharan Africa (SSA) to improve real-time diagnosis of HIV-associated pediatric cancers, because this is a prerequisite for evidence-based treatment and clinical/translational research. Diagnosis of cancer in children in SSA is a major challenge because of scarcity of local skilled personnel, facilities for obtaining tissue biopsies, and laboratory platforms for pathology analysis. The result is that for many children with suspected cancer a diagnosis is made based on clinical features only. If a biopsy is obtained, morphological examination using Hematoxylin & Eosin (H&E) stain is often the only test performed. In our study of 324 with HIV infection and diagnosed with KS at BIPAI centers in Uganda, Malawi, Tanzania and Botswana from 2008 ? 2014, 141 (43%) of the children were diagnosed based on clinical history and examination only. The overarching aim of this project is to implement and evaluate harmonized diagnostic strategies in PARCA sites. Aim 1: Evaluate the adequacy of biopsies and diagnostic accuracy of the current Global HOPE Uganda diagnostic strategy for pediatric cancer tumors. We will retrospectively assess the proportion of adequate biopsies, and repeat or escalation to open surgical biopsy among 400 children with HIV-associated cancers. To determine the accuracy of the current diagnostic strategy, we will perform gold-standard diagnostic assays by United States standards on archived FFPE tissues from these 400 cases. Aim 2: Determine the feasibility of standardizing the diagnostic algorithm across multiple sites by implementing a similar algorithm in Malawi. We will implement a similar diagnostic approach in Malawi by training medical personnel to use a similar biopsy strategy and expanding the flow cytometry and IHC antibody panels to mimic those performed in Uganda. To ensure accuracy and consistency across sites in preparation for implementation of standardized cancer treatment and research protocols across SSA sites, we will implement a virtual pathology platform to enable sharing and central review of images. The virtual pathology network will also serve as a platform for ongoing training of pediatric pathologists and technicians. Aim 3: Improve accuracy of cancer diagnosis at SSA sites by designing, testing, and implementing novel diagnostic methods. We will test and validate novel molecular assays of established diagnostic biomarkers to improve timeliness and specificity of the diagnosis using platforms and procedures that are sustainable in the SSA setting. Consideration will be given to cost, complexity, and turnaround time.